摘要:

AbstractIn the design of members with flaws, it is necessary to keep the stress intensity factorKof any sharp crack below the fracture toughnessKcrof the materials. Stress‐intensity factor equations for the more common basic specimen geometries and various loading conditions are available in the literature. The application of these equations to complex structures involves geometric problems such as the identification of the outline of each member and the sizing of the equivalent specimen for each flaw. The paper gives a response to such difficultie

ISSN:1069-8299    

DOI:10.1002/cnm.1640100402

出版商:John Wiley&Sons, Ltd    

年代:1994

数据来源: WILEY

摘要:

AbstractWe propose in this paper a nine‐point, fourth‐order difference method for the numerical solution of the quasilinear Poisson equation\documentclass{article}\pagestyle{empty}\begin{document}$$ Au_{zz} + \frac{1}{r}u_r + Bu_{rr} = f\left({r,z,u,u_r,u_z} \right) $$\end{document}with appropriate boundary conditions. The method is based on five evaluations off. The numerical results of four problems obtained using this method are listed. The results demonstrate the fourth‐order accuracy of the m

ISSN:1069-8299    

DOI:10.1002/cnm.1640100403

出版商:John Wiley&Sons, Ltd    

年代:1994

数据来源: WILEY

摘要:

AbstractSingularly perturbed second‐order elliptic equations with boundary layers are considered. These may be considered as model problems for the advection of some quantity such as heat or a pollutant in a flow field or as linear approximations to the Navier‐Stokes equations for fluid flow. Numerical methods composed of central‐difference operators on special piece‐wise‐uniform meshes are constructed for the above problems. Numerical results are obtained which show that these methods give approximate solutions with error estimates that are independent of the singular perturbation parameter. An open theoretical problem

ISSN:1069-8299    

DOI:10.1002/cnm.1640100404

出版商:John Wiley&Sons, Ltd    

年代:1994

数据来源: WILEY

摘要:

AbstractA simple, yet storage‐effective ‘linear’ programming code is given. The assumption of non‐negative variables is bypassed without increasing the size of the problem. Furthermore, the objective is allowed to be summed over not just linear, but also concave, functions. A specific truss topology optimization example i

ISSN:1069-8299    

DOI:10.1002/cnm.1640100405

出版商:John Wiley&Sons, Ltd    

年代:1994

数据来源: WILEY

摘要:

AbstractIn the paper we present a superconvergent patch recovery technique for obtaining higher‐order‐accurate finite‐element solutions and thus a postprocessed type of L2norm error estimate. Two modifications make our procedure different from the one proposed by Zienkiewicz and Zhu (1992), in which higher‐order‐accurate derivatives of the finite‐element solution at nodes are determined. Firstly, the recovery process is made for element, not for nodes. An ‘element patch’, which represents the union of an element under consideration and the surrounding elements, is introduced. Secondly, the local error estimate is calculated directly from the improved solution for this element. Numerical tests on both 1D and 2D model problems show that this method can provide an asymptotically exact a posteriori L2norm error estimate if the used element possesses superconvergent points fo

ISSN:1069-8299    

DOI:10.1002/cnm.1640100406

出版商:John Wiley&Sons, Ltd    

年代:1994

数据来源: WILEY

摘要:

AbstractA new approach to developing serendipity quadrilateral infinite elements is presented. Using these elements universal matrices for quasiharmonic equation are developed. For a particular member of the family these matrices are independent of the size and shape of the element. Using these matrices the element stiffness matrix can be generated in a simpler manner by taking into account the size and shape of the element.

ISSN:1069-8299    

DOI:10.1002/cnm.1640100407

出版商:John Wiley&Sons, Ltd    

年代:1994

数据来源: WILEY

摘要:

AbstractA new global secant relaxation (GSR)‐method‐based improvement procedure is used to improve the overall convergency performance of the modified Newton‐Raphson iteration in carrying out the solution of discrete systems resulting from the finite‐element discretization of a certain class of structural problems involving non‐linear deformation

ISSN:1069-8299    

DOI:10.1002/cnm.1640100408

出版商:John Wiley&Sons, Ltd    

年代:1994

数据来源: WILEY

摘要:

AbstractTheoretical and experimental analysis of free‐surface electrohydrodynamic flow is fragmented and incomplete. Simulation studies of this phenomenon are further limited by the inherent complexities in the modelling process. In this note a mathematical model is developed to analyse free‐surface electrohydrodynamic flow in two dimensions, and preliminary results of the simulation are described. The configurations examined include electrified conducting surfaces, the dielectrophoretic forces, and a conducting jet. The simulation is compared with analytical results in the first two investigations and is shown to be quite accurate. In the last simulation it is demonstrated that in the initial formation of a conducting jet, a 10 per cent increase in applied voltage results in about a 10 per cent increase in fluid veloc

ISSN:1069-8299    

DOI:10.1002/cnm.1640100409

出版商:John Wiley&Sons, Ltd    

年代:1994

数据来源: WILEY

ISSN:1069-8299    

DOI:10.1002/cnm.1640100410

出版商:John Wiley&Sons, Ltd    

年代:1994

数据来源: WILEY

ISSN:1069-8299    

DOI:10.1002/cnm.1640100411

出版商:John Wiley&Sons, Ltd    

年代:1994

数据来源: WILEY